package com.tdd;

import static org.junit.Assert.assertEquals;

import java.math.BigDecimal;

import org.junit.Before;
import org.junit.Test;

public class RpnCalculatorTest {
	private RpnCalculator rpnCalculator;

	@Before
	public void init() {
		rpnCalculator = new RpnCalculator();
	}
	
	@Test
	public void newlyCreatedCalcualtorHas0Value() {
		assertEquals(0, rpnCalculator.peek());
	}
	
	@Test
	public void numbersEnteredAreReturnedLifo() {
		RpnCalculator rpnCalculator = new RpnCalculator();
		rpnCalculator.push(new BigDecimal(3));
		rpnCalculator.push(new BigDecimal(2));
		rpnCalculator.push(new BigDecimal(1));
		
		assertEquals(BigDecimal.ONE, rpnCalculator.pop());
		assertEquals(new BigDecimal(2), rpnCalculator.pop());
		assertEquals(new BigDecimal(3), rpnCalculator.pop());
	}
}
